What would you like to do?

What are the oxidation numbers for CrO4-2?

already exists.

Would you like to merge this question into it?

already exists as an alternate of this question.

Would you like to make it the primary and merge this question into it?

exists and is an alternate of .

2- is the oxidation number.
Thanks for the feedback!

Why does oxygen have an oxidation number of -2?

Oxygen has 6 valence electrons. It needs to gain two more to complete octet. So oxygen has an oxidation number of -2 when it gains 2 electrons (as in oxide ion)

What is oxidation number of CR2O7-2?

Overall the anion has an oxidation number of -2, the same as itscharge. The Cr is +6 and the O are all -2.